Abstract: Under the premise of contribution margin varying randomly,distributed power generation first serves self-use as well as its economic characteristics are considered. Based on the real options theory,the option pricing model for investment opportunity in distributed wind power stations is established,and the contribution margin threshold,optimal investment scale,the option value and expected waiting time of delayed investment are solved. A case study is presented to validate the main conclusions,and give the influence variation of different parameters on the equilibrium state. It is found that for distributed wind power stations with limited investment time,contribution margin threshold,optimal investment scale,and expected waiting time are all positively related to the expected increase and variation rate of contribution margin. Meanwhile,the option value of delayed investment has different correlations with these two rates,and the significances of the influences are different. In a certain condition and range of contribution margin,the option value of delayed investment and expected waiting time increases and decreases respectively,with the increase of the proportion of generated wind power for self-use or initial contribution margin. However,the proportion of generated wind power for self-use does not influence the optimal investment scale,and the initial contribution margin does not influence the contribution margin threshold and optimal investment scale. The decision-maker's optimal decision should take both contribution margin threshold and optimal investment scale into consideration.

Key words: distributed wind power, real options, contribution margin threshold, investment threshold, expected waiting time